Linear hydraulic motors to be driven by water from a municipal or rural supply system are well known in the art and are used in all cases where no electricity is available, where a certain waste of water is of no importance, and where an internal combustion engine would be too cumbersome for the relatively small power output required. These hydraulic motors work on the principle of a reciprocating piston or diaphragm assisted by flexible means such as steel springs, rubber cushions and the like. Water inlet and/or outlet are either controlled by valves or are covered and uncovered by the reciprocating piston or its extension. In another type of motor, flip-flop valves are used for closing and opening the water inlet and to control the piston or diaphragm movement.
The main drawback of this type of apparatus is that these flexible means deteriorate and change their modulus of elasticity with time so that they require frequent exchange and replacement.
In view of the above it is the object of the present invention to provide a linear hydraulic motor with a minimum of moving parts and without the use of flexible parts. Another object is to provide such motor in robust construction at a relatively low price.